Recorder with movable chart carriage



Feb'. 16; 1954 D. A. YOUNG ETAL RECORDER WITH MOVABLE CHART CARRIAGE Filed May 2s, 1947 4 Sheets-Sheet l ATTOR N EY Feb. 16, 1954 D. A. YOUNG ETAL 2,669,501

RECORDER WITH MOVABLE CHART CARRIAGE Filed May 28, 194? 4 Sheets-Sheet 2 67 Tm 4 /9c 4 7 l 4/274 ,3.9, 4&1

/3 Z7? 27a 37 -276 W 33 23\ Inga/flan l A f/ ,7 C B L 39a 57 /5 IHK 1 l 35 INVENTORS .Doug/05.514. Young',

lawrence .7.' Unas and John Afa/weert 49 ATTORNEY Feb. 16, 1954 D. A. YOUNG Erm. 2,669,501

v RECORDER WITH MOVABLE CHART CARRIAGE Filed May 28, 1947 4 Sheetshoet 5 mvENToRs WITNESSES. Doug/055A. Ya ung',

.Lawrence J2 l una: and abn Hala-werf? ATTORNEY Feb. 16, 1954 D A, YOUNG ETAL 2,669,501

RECORDER WITH MOVABLEI CHART CARRIAGE Filed May 28, 194'? 4 Sheets-Sheet 4 E99. y E Figa INVENTORS lawrence un as and .I6/1n Na fn/eer',

ATTOR NEY Patented Feb. 16, 1954 RECORDER WITH MOVABLE CHART CARRIAGE Douglass A. Young, East Orange, Lawrence J. Lunas, Cedar Grove, andI John Walsweer, Glen Ridge, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh,A Pa.,J a corporation of Pennsylvania Application May 28, 1947, Serial N0. 750,935

25 Claims. 1

This invention relates to recording devices, and it'- has particular relation to recording devices employing record-ing pens for marking a record on a movable chart strip.

In many applications of recording devices, it is desirable. to mount the recording devices in very compact arrangements. For example, on switchboard panels, it is desirable to mount recording instruments on centers spaced apart by only six inches. At the same time, it is also desirable to employ a chart strip providing a wide scale. Ona recording device suitable for mounting on six-inch centers, a chart strip preferably should be capable` of providing a record at least four inches in length.

The problem of designing a compact recording device is further complicated by the service requirements thereof'. A recording device requires attention at intervals for the purpose of servicing or replacing recording pens and chart strips. If a spring motor is employed for advancing the chart strip, the motor must be rewound at regular intervals. Also, inkwells must be lled and instrument adjustments made.

1'n accordance with the invention, a recording device is provided which may be completely serviced from the irontA thereof. To this end, the recording device is divided into two major components which may be termed', respectively, a fixed unit and a removable unit. The Xed unit is designed to be mounted permanently on a suitable mount, suchv asv a switchboard panel. It contains a recording pen, mechanism such as an electrical instrument for actuating the recor ingA pen, an i'nlrwell` for supplying ink to the recording pen, a scale if an indication of the movement oi the recording pen is desired', and mounting means fory mounting the movable unit.

The movable unit comprises a chart carriage for receiving advancing a chart strip with respect to the recording pen. This chart carriage is normally maintained in operative position with respect to the recording pen. However, to facilitate servicing operations, the chart carriage mayv bel moved in a l-lrst direction to clear the recording pen, and-1 subsequently tilted to a service position with respect to the iiXed unit, for the purpose of exposing parts of the recording device. When in the service position, the chart carriage may be removed froml the nxed unit in response to relative movement therebetween.

'lo facilitate inspection ofthe chart stri-p and rreplacement thereof, mechanism isf provided for normal-ly retaining a rewind roll operative position. When a servicing operation is desired, ejector mechanism may be actuated to eject the rewind roll from its operative position to an accessible service position.

The invention further contemplates the provision of a recording pen which is readilyr removable from the iront of the recording device. The recording pen is designed to provide a light structure and good contact with the chart strip during sudden movements of the recording pen.

The inkwell for the recording pen normally is mounted in a position which is relatively inaccessible. However, a suitable linkage is provided for moving the inkwell' to a readily accessible service position. The same linkage may be employed' for moving a scale, if employed, to a position clear of other parts requiring servicing. Preferably, the linkage is interlocked with the chart carriage to prevent operation thereof until the chart carriage is removed from its operative position.

It is, therefore, an object of they invention to provide a compact and accessible recordingdevice.

It a further object of the invention to provide a recording device'- having a recording pen and` having ar chart carriage movable in a iirst direction with respect to the recording pen to an intermediate position and pivotable from the intermediate position about an axis transverse to the first direction.

Itv is an additional object oi the invention to provide a recording device having mechanism for ejecting a rewind roll employed in the device.

It is another object of the invention to provide a recording device having linkage for moving an inkvvel-l from a relatively inaccessible position to an accessible service position.

It. is also an object of the inventionA to provide a recording device having. a scale which may be moved for the purposeof' exposing other parts of the recording device.

Itis a still further object of the invention to provide a` recording device having a recording pen. element of light Weight.

It is an additional object ofthe invention to provide a recording device having all parts requiring service readily accessible from the front of the recording device.

Other objects of the invention will be apparent from. the following' description taken conjunction With the accompanying drawings, in which:

Figure 1 isa View in perspective, with parts broken away, of a. recording device embodying the invention;

Fig. 2 is a view in perspective of the recording device shown in Fig. 1, having the parts thereof in different relative positions;

Fig. 3 is a view in perspective of the recording device shown in Fig. l, showing still different relative positions of the parts thereof;

Fig. 4 is a detail view in elevation, with parts broken away, showing a recording pen and the upper part of an instrument suitable for the recording device of Fig. l;

Fig. 4A is a view in section taken on the line IVA-VA of Fig. 4;

Fig. 5 is a view in top plan of the mechanism shown in Fig. 4 with parts added;

Fig. 5A is a view in side elevation taken on the line VA- A' of Fig. 5;

Fig. 6 is a view in side elevation, with a side plate removed, of a chart carriage suitable for the recording device of Fig. l;

Fig. 7 is a view in perspective showing an inkwell and linkage associated therewith, suitable for the recording device of Fig. 1;

Fig. 8 is a view in side elevation of a casing suitable for the recording device of Fig. 1;

Fig. 9 is a View in front elevation of the casing illustrated in Fig. 8;

Fig. 10 is a view in rear elevation with parts broken away of the door employed for the casing of Fig. 8; and

Fig. 11 is a detail view of attaching means for a removable gear employed in the recording device of Fig. 1.

Referring to the drawings, Figure 1 shows a recording device which may be divided into two principal components. These consist of a xed unit i which may be mounted on any suitable mount, such as a Switchboard panel, and a movable unit 3 which is shown in operative position with respect to the fixed unit I and which may be moved with respect thereto.

As shown more clearly in Fig. 3, the xed unit I includes two parallel spaced side walls 5 and .'I which are secured to a base member 9. In addition., a front wall iI extends between the side walls 5 and l. These walls may be formed of any suitable sheet material, such as sheet steel, brass, or aluminum. The enclosure formed by the walls and base member contains a mechanism for actuating a recording pen I3 in accordance with a quantity to be recorded. The top portion of such mechanism is indicated in Fig. 4 by a reference character I5. As representative of mechanisms suitable for the recording device, an ammeter, a voltmeter or a wattmeter may be employed. Electrical connections for an electrical instrument, if employed, may be passed through the base member 9, but are not illustrated in the drawings.

As shown in Fig. 4, the electrical instrument i5 has a vertical shaft I'! which is rotated in accordance with the magnitude of a quantity to be recorded. A pen bracket I3 is secured to the shaft i? in any suitable manner for rotation therewith. This bracket may have substantially a channel cross-section to provide a rigid structure of low weight. The channel may be constructed from light-weight material such as Duralumin or sheet aluminum, and may have side flanges ISA bent at right angles to a top wall iQB. As illustrated in Fig. 4, the pen bracket has secured thereto by bolts 2c a bushing 2i which is proportioned to receive therein the shaft Il. A setscrew 23, which is in threaded engagement with the bushing 2l, engages the shaft I 'i to secure the bushing thereto.v some 4 cases it may be desirable to construct the bushing 2l from insulating material.

At its front end, the pen bracket has its flanges enlarged to provide a pair of spaced parallel bearing supports 25 and 2'I. Each of the bearing supports is provided with a notch 25a or 21a, for receiving knife-edge pivots 29 and 3| which are secured to the recording pen I3. The notches are substantially larger than the pivots to provide ample clearance for parts of the pivots other than the knife edges. The shape of the notches will be understood by an examination of the notch 21a in Fig. 4. It will be noted that the notch has a surface 2lb engaging the pivot 3i. The surface 2lb may be provided by a Phosphor bronze insert 2Ic which is riveted or otherwise secured to the bearing support 21 if a material other than that of the supports is desired for bearing purposes. A similar insert 25o may be provided for the bearing support 25.

By inspection of Figs. 4 and 5, it will be observed that the pivots 29 and 3i cooperate with the bearing supports 25 and 21 to mount the recording pen I3 for pivotal movement about a horizontal axis with respect to the pen bracket i9. It will be observed further that this horizontal axis is spaced from the vertical axis of the shaft l'l by a distance A which is a major part of the distance A+B between the pen point i3d of the recording pen and the vertical axis of the shaft Il. In a unit actually constructed, the distance A was approximately two-thirds of the total distance A+B. This construction facilitates the design of an extremely light recording pen i3.

The recording pen comprises a small capillary tube 33 which extends from the pen point |3a toward the shaft I1. The tube 33 has its end i nearest the shaft Il bent downwardly for reception in an inkwell 35. Consequently, ink from the inkwell 35 is supplied through the tube 33 to the pen point i3d for application to a chart strip C positioned beneath the pen point. The inkwell may be located approximately midway between the shaft Il and a Vertical line intersecting the horizontal axis defined by the pivots 2a and 3l.

It will be noted further that the pivots 29 and 3l are disposed between the ends of the tube 33. Consequently, portions of the tube 33 on opposite sides of the pivots tend to balance each other. Additional balancing is obtained by means of the weight of a coil spring 3'! having turns which frictionally grip the tube 33. The parameters may be selected to permit location of the spring 3'? on either side of the horizontal axis. As shown in Fig. 4, the spring is on the rightof the axis. By inspection of Fig. 1, it will be observed that the position of the spring 3l is readily adjustable along the tube 33 for the purpose of adjusting the balance of the recording pen.

The positions of the pivots 29 and 3l are so selected that centrifugal force resulting from rotation of the shaft il urges the pen point I3@ into firmer contact with the chart strip C. A bracket 39 secures the pivots to the tube 33. It will be noted that the axis of rotation of the tube 33 established by the pivots 29 and 3I is substantially below the tube. The displacement of the axis relative to the tube is so related to the parameters of the pen-assembly that moments about the axis produced by centrifugal forces resulting from rotation of the shaft I 'I maintain the pen in contact with the chart strip C. With the construction illustrated in Figs. 4 :and 5, it has been found feasible to reduce the 'static pressure of the recording pen against the chart ystrip vC appreciably below values conventionally employed. For example, `a pressure of Aonly milligrams has been found ladequate in a .recording device built and tested.

Since the recording pen is of extremely light construction, and since lthe pivots 29 and `3I are relatively close to the pen point I3a, irregulari- 'ties of the surface of the chart strip C' do not tend to force the pen point appreciably away from the chart strip. As a matter of fact, in actual operation, it has been found that violent movement of `the recording pen about the axis of l the vshaft I1 does not prevent the production of a legible record on the vchar-t strip. Preferably, the bracket I9 and associated pen assembly are balanced relative to the shaft I1, as by a counterweight CW adjustably -secured to the bracket I9.

The pen bracket I9 is provided with a guide tongue 4I for guiding the recording pen relative to the bracket I9 into its operative position. Openings e and 21e lin the supports 25 and '21 permit introduction of the pivots into the notches `25a and 21a. In order to remove the recording pen, itis merely necessary to raise lthe pen ysufficiently for the pivots 3| and -29 to clear the -notches 25a and 21a. The recording pen Vthen is withdrawn toward the front of the recording device.

A leaf spring 42 may have one end secured to the top wall IQB in any suitable manner. 'Iliis spring `has a resilient portion positioned Aslightly above the bracket y39 to prevent accidental displacement of the knife edges from the associated notches. The bracket may be moved upwardly to deflect the spring when it is desired to vremove the pen from its operative position.

If an indication of the movement of the recording pen is desired, a target 45 may be secured to the end of the recording pen. 'This .target preferably is constructed of a light-weight `material such as sheet aluminum suitably 'bent or formed, and is positioned to rotate across the front of Ja scale 41 as the shaft I'1 of Fig. 4 rotates.

'The pen structure is shown vin somewhat .greater detail in the copending application of D. .A. Young et al., `Serial No. 750,936, filed of veven date herewith and assigned to the same assignee.

In many instruments employed for recording devices, a zero adjuster mechanism is provided. The zero adjuster mechanism may be located at vany desired point. Conveniently, it may be located adjacent the lower end of the shaft I1, as viewed in 4, and may be similar to the zero adjuster mechanism shown in Fig. 22 of the L. J. 'Lunas patent application, Serial No. 570,028, flied December 27, 1944, now Fatent No. 2,508,410, Aand assigned toy the same assignee. For example, if the instrument I5 of Fig. 4 is similar to the instrument shown in Fig. 22 of the aforesaid Lunas patent application, it may have a control spring 49 and a Zero adjuster arm 53 located adjacent the lower end of the shaft I1 in the manner described in said patent application.

fzero position of the associated instrument.` Prefbracket.

6 erahly, the arm 53 is adjustable from the front of the recording device, as indicated in Fig. 3.

A pair 'of stops I9a and ISb (Fig. 5) are provided for limiting movement of the pen bracket I9 to a predetermined angle about the axis of 'the shaft I1. These stops are positioned in the .path of a pin I 9c 'which is secured to the pen The stops ISa and I9b are pivotally mounted by rivets IBd on a strut I9e which is Vsuitably secured to the walls 5 and 1 by machine .screws 54 (Figs. 5a, 7 and 3). A spring wire I9f is coiled around a post 19g secured to `the strut and has its ends positioned in holes I9 f in the stops I-Sa and I9b for urging the stops respectively in clockwise and counterclockwise directions as 'viewed in Fig. 5. The spring wire urges abutments |911, and I 97', which are secured `respectively to the stops ISa and |913 into engagement with adjusting screws I9k and I 9m. These screws are in `threaded engagement with ya bracket Isn secured to the strut ISe and are adjustable from the front of the recording device for positioning properly the stops ISa and I'Sb. For example, rotation of the screw I 9m .rotates the stop 'I9b about the axis of the associated rivet Id.

The inkwell 35 in operative position is relatively inaccessible from the front of the recording device. In order to facilitate servicing of the inkwell, linkage is provided for moving the inkwell from its operative position to a service position wherein it is readily accessible from the Ifront of the recording device.

As shown in Fig. 4, the inkwell 35 is provided with a lip 55 for retaining the inkwell kon a bracket 51. B'y lifting the inkwell with respect to the bracket 51, the inkwell can be detached completely from the bracket.

.As shown in Figs. 3 and 7, the bracket 51 has its ends 51a `and 51h bent parallel to the side Iwalls 5 and 1 of the fixed unit. 'These ends 51a and 51h are each pivotally attached to one of a pair of similar links 59 and 6I by means of suitable rivets 53. The links 59 and 6I are pivotally attached lrespectively to the side walls 5 and 1 by means of pins 65. If desired, a friction disc 66, such as a leather disc, may be interposed between the upper end of the link 59 and the wall 5. The link may be urged towards the wall 5 in any suitable manner to compress the disc 55 and hold the link in any position of adjustment. For example, a rod 06a may have recesses 6611 at each end for receiving the pins 65. A helical spring in one or both of the recesses urges a collar 660 centrally disposed on each pin towards the associated link.

In order to maintain the inkwell 35 level during movement thereof, a lever 61 is pivoted to .the side wall 5 by means of a rivet 69 and to the end 51a of the bracket 51 by means of a rivet 1I. The lever 51 provides a link 61d for the inkwell which is parallel and equal in length to the link 59. Consequently, this parallel linkage prevents the inkwell from tilting during movement thereof from operative to service positions.

By inspection of Fig. 7, it will be noted that the lever '61 comprises a portion 61h which is perpendicularly related to the link 61a. Movement of the inkwell may be effected from the front of the recording device by grasping the portion 51h and moving the lever 61 to the desired position. When the inkwell is in operative position (shown dotted in Fig. 7 and in full lines in Fig. 4) a lip 61o on the lever 61 is positioned in front of the front Wall I of the xed unit.

The inkwell 35 is provided with a detachable cover 13 which has lips 15 resting on the upper edge of the inkwell. The cover 13 may be removed by lifting it from the inkwell 35. It will be noted that the cover 13 has an arcuate slot 11 for reception of an end 33a of the tube 33. By reference to Fig. 4, it will be noted that the end 33a of the tube 33 is bent in the direction of travel of the inkwell 35 during its movement from operative position. This facilitates withdrawal of the tube 33 through the slot 11 in the cover 13 during such movement.

By reference to Fig. l, it will be noted that the scale di extends over a substantial part of the front of the recording device. In order to provide greater access for parts of the recording device the scale, the scale may be pivotally mounted for movement from the position illustrated in Fig. l to the position illustrated in Figs. 3 and 7. To this end, the scale may be pivotally secured to the side wall 1 by means of a rivet 19. and it may be rigidly secured to the upper part of the lever 61. Consequently, actuation of the lever d1 to move the inkwell 35 from its operative to its service position simultaneously rotates the scale 41 from the position illustrated in Fig. 1 to the position illustrated in Figs. 3 and '7. In the latter position, the recording pen i3 and the inkwell 35 are wholly accessible from the front of the recording device.

If the scale d1 is of light-permeable material, it may be illuminated by means of an electric lamp 8|. Preferably, the scale is of opaque material, and is illuminated by light reflected from the lamp 8i by the rear surface 82a of a cross bar 82 which extends between the Walls 5 and 1. This rear surface may be properly shaped and painted white to reflect light. As shown in Fig. '7, the electric lamp 8| is mounted in a socket 84 secured to a bracket or holder 83 which is pivotally attached to the side wall 5 in any suitable manner as by means of a rivet 85. If

it is necessary to replace a lamp 8|, the holder B3 may be pivoted about the rivet 85 to place the lamp 8| in a position more accessible from the front of the recording device. The holder 83 has a bump or protuberance 86 projecting towards the wall 5. This protuberance is proportioned for entry into a hole 86a provided in the wall 5 to retain the holder in operative position. Resilience of the holder permits the protuberance to ride out of the hole 86a when the holder is nivoted about the rivet 85. Flexible conductors 81 are provided for connecting the lamp 3| to a suitable source of electrical energy.

As previously explained, the recording device includes a movable unit or chart carriage 3. As shown in Fig. l, the chart carriage 3 includes two spaced parallel plates 9| and 93 which may be formed of any suitable sheet material, such as steel, brass or aluminum. The plates 9| and G3 are rigidly secured to each other in any suitable manner as by means of spacing rods 95 which are secured to the plates by means of machine screws el. The chart strip C is fed from a supply roll se over a feed roll or drum iii! to a rewind roll |93. The mechanism for guiding and advancing the chart strip Cv may `be described more clearly by reference to Fig.

6, wherein the path of the chart C is illustrated by a dot anddash line. Y Y v V The supply roll 99 has a shaft |00 which projects from the ends of the supply roll. The ends of the shaft are received respectively in slots I |35 which are formed in the plates 9| and 93. By inspection of Fig. 6, it will be noted that the slots |65 are inclined downwardly, and have lower portions |06 which are substantially vertical. Consequently, gravity tends to retain the supply roll 99 at the bottom of the portions |06 of the slots |35. However, the supply roll 39 may be removed readily through the slots for servicing or replacement. A shield plate |01 surrounds the lower face of the supply roll to protect the chart strip.

The chart strip C from the supply roll 99 is fed under a guide roll |09 and over a table ||0. The table HB supports the chart strip under the recording pen to present a flat horizontal surface for reception of a record.

From the table il, the chart strip passes over the feed roll or drum lili. This feed roll is mounted for rotation about the axis of a supporting shaft Iii. It will be noted that the feed roll IM has uniformly spaced sprocket teeth ||3 positioned around each end of the roll. These sprocket teeth enter holes H5 (Fig. l) which are punched in the edges of the chart strip for the purpose of advancing the chart strip in a manner well understood in the art. Clips ||1 and ||9 are positioned adjacent the edges of the feed roll ||l| for the purpose of retaining the chart strip in position during feeding operations. It will be noted that these clips have slots |20 which permit passage therethrough of the sprocket teeth H3. These clips may be pivoted about an axis 2| (Fig. 6) for movement away from the feed roll lill to permit ready removal and replacement of the chart strip in a manner Well understood in the art.

As further shown in Fig. 6, the chart strip C in leaving the feed roll |0| passes over a vertical table |23. This table supports the chart strip for reception of any desired notation or additional record information which the operator may desire to write or mark on the chart strip. From the table |23, the chart strip C passes to the rewind roll |03.

The chart strip is advanced by means of a suitable motor |21. This motor may be either of a spring-wound type or of the synchronous electrical type. Electrical connections |29 are provided for the purpose of energizing an elecvtrical motor if such a motor is utilized. The connections |29 are iiexible and terminate in a plug 3| for reception in a socket (not shown) carried by the Xed unit. Consequently, if the chart carriage is to be removed from the fixed unit, electrical connections may be readily interrupted by withdrawal of the plug |3| from its socket.

The motor |21 has a pinion |33 which engages a gear |35 mounted for rotation on a shaft |31. The gear |35 is rigidly attached to a gear |39 for rotation as a unit about the same axis. The gear |39 engages a gear |41 which is attached to the feed roll |0| for rotation therewith about the axis of the shaft Consequently, the motor |21 drives at a substantially uniform rate of rotation the feed roll im and uniformly advances the chart strip C. In order to facilitate manual adjustment of the feed roll |U| for timing or other purposes from the front of the recording device, a gear |42 meshes with the gear Mil. The gear |52 is mounted for rotation about the axis of a rivet or screw |4211, .which secures the gear to the plate 9| (Fig. 1). An operator may rotate the 9, geark |42y manually for the purpose of adjusting the feed roll.

Ihe motor |21 also is employed forl rotating the rewind roll |03. To thisl end, a drive pulley |43 is mounted for rotation abou-t the shaft |31. Thisdrive pulley isv coupled to the gear |35y through a conventional friction clutch (not shown) which permits the pulley to slip with respect to the gear |35 when an excessive load is applied to the drive pulley. The drive pulleyis coupled through a belt |45 to a driven pulley |41. The driven pulley and a gear |49 are mounted for rotation as a unit about a shaft |'5|. The gear |49 engages a gear |51lv which is secured to the rewind roll |03 for rotation therewith` about the axis of a supporting shaft |53.

It will be understood that as paper is wound on the rewind roll |03, the diameter of the paper wound on the roll increases and the rate of rotation of the rewind roll necessary to receive the uniformly advanced chart stripA decreases. The gear and pulley drives are so selected that the rewind roll |03 rotates with sufficient rapidity to receive the chart strip when the rewind roll issubstantially empty. As the rewind roll lls, the friction clutch betweenl the drive pulley and the gear |35l slips. Becausey of this slippage, the rewind roll |03 is always urged in the proper direction to take upA more slack in the chart strip but does not stall the motor as the rewind roll fills. If desired, the friction clutch may be eliminated and slippage of the belt |45 may be relied on to prevent stalling of thel motor as the rewind roll fills. As illustrated, the belt |45 is formed of a spiral spring which may be constructed of a suitable metal, such as steel or brass.

In order to facilitate removal and replacement of the rewind roll |03 from the front of the recording device, the shaft |53 has extensions resting' on two guide rails |55 and |51 which are secured, respectively, to the plates 9| and 93 (see Fig. 2). The rails cooperate, respectively, with latches |59 and 6| for controlling the retention and ejection of the rewind roll. The latches |59 and |6| are rigidly secured to each other for movement as a unit. The structure of the rails and latches may be understood byr reference to. Fig. 6.

In Fig. 6, it will be noted that the guide rail |51 is inclined downwardly. Consequently, if the rewind roll |03 were free to move, it would tend to move under the influence of gravity from. the position illustrated in Fig. 6 to a position wherein the shaft |53 abats. a stop les. A similar stop is provided on each guide rail. In this position, the rewind roll |03 would be fully accessible from the front. It could be lifted from the guide. rails for inspection of an early portion of the chart strip or it could be removed for replacement purposes.

In order to retain the shaft |53 in the position illustrated in Fig; 6, each of the guide rails is provided with a hook |65 which prevents movement of a shaft |53 in. an upward direction or to theeright as viewed in Fig. 6. Each of the latches is provided'. with a retaining lip |61 for retaining the shaft |53 in the associated hook |65. Con-LA sequently, when the latches are raised, the shaft |53 isk free to move from the position illustrated in Fig. 6 to a position in engagement with the stops |63.

As previously explained, the latches are rigidly connected to each other in any suitable manner asby means of rods |69 and |1| which may be riveted to the latches. Each of the latches |59 and IGI- is secured to its associated side plate 9| or 93 by any suitable means such as a machine screw |13 for rotation with respect to the plate about the axis of the machine screws. Each latch is biased towards the position illustrated in Fig. 6 by means of a helical spring |15 extending between the rod |69 and a rod |11 which is secured to the side plates 9| and 93. In order to facilitate movement of the latches from the front of the chart carriage,l the front edge of the latches may be serrated or roughened, as indicated in Fig. 6 by the reference character |19. Preferably, however, the latches have an operating rod connecting their exposed ends. This rod |80 not only assists in securing the latches rigidly to each other, but it is readily grasped for releasing the roll |03.

When it is desired to inspect a portion of the chart strip located on the rewind roll |03, the latches are rotated in clockwise direction as viewed in Fig. 6 to remove the lips |51 from the associated shaft |53. lnis frees the roll |03 for movement down the rails |55 and |57. Continued rotation of the latches 15| brings the rod |89 into engagement with the rewind roll |03 and positively forces the rewind roll |03 down the rails towards the stops |53. rlhe gears |49 and |52 are so located that the desired, movement of the rewind roll |03 disengages the gears. The rewind roll next may be lifted over the stops |53 and dropped to clear the rod |80, if the rod is employed.

In order to replace the rewind roll, the rewind roll is placed on the rails adjacent the stops |63 and merely forced to the right as viewed in Fig. 6. During such movement, the ends of the shaft |53 force the latches in a clockwise direction as Viewed in Fig. 6' until the shaft |53 is` received within the hooks |05. The latches then move in a clockwise direction under the influence of the spring |15 to retain the shaft |53 in operative position.

If desired, the roll |03 may be driven from the gear |52 through mechanism of the windowshade roller type which is well known in the art. With such mechanism the roll 93 is driven from the gear |52 through a long helical or spiral spring of the window-shade type. The chart strip C may be pulled from the roll against the resistance of the spring for inspection. On release of the chart strip, the spring rewinds it on the roll.

AsY clearly shown in Fig. 6, the plate 9| has its bottom congured to provide a cam surface |8| which at its lower end` terminates in a slight recess |33. In addition, the bottom of the plate 9| is provided with a slot |85. As shown clearly in Figs. 1, 2 and 3, the plate S3 similarly has its lower end configured to provide a similar cam surface lilla, a similar recess |33 and a similar slot |a. The cam surfaces |8| and Hilo. are intended to guide the chart carriage 3 between the operative position relative to the xed unit which is illustrated in Fig. l and an intermediate position which is illustrated in Fig. 2. To this end each of the side walls 5 and I is provided with a cam follower in the form of a roller |81 or |81a which is rotatably secured to the associated side wall by means of a suitable rivet |89. When the chart carriage is in the position illustrated in Fig. 1, the cam followers |81 and |8'1a are received, respectively, in the recesses |83 and-|83a to retain. the chart carriage in operative position.

When the bottom of the chart carriage is moved forwardly, the cam followers |81 and |8'la move out of the recesses |83 and |83a to engage the inclined cam surfaces IBI and lilla. Because of the recesses, a substantial force must be applied to effect this movement of the chart carriage. The cam surfaces next ride down the cam followers to guide the chart carriage to the intermediate position illustrated in Fig. 2.

In order to effect the desired forward movement of the chart carriage, e. lever |99 is provided comprising a pair of plates E9| and |93 which are pivotally attached respectively to the support formed by the side walls and l in any suitable manner as by means of a shaft |95 which extends through both of the side walls and which passes through a spacing sleeve |91. The ends of the shaft |95 may be upset or riveted to secure the parts in the positions illustrated in Fig. 1. The plates |93 and |9| also have secured thereto a pair of rods |99 and 20| to form the rigid lever |95. It will be noted that the rod 29| in the position illustrated in Fig. 1 forms a handle which is received in notches 293 and 205 formed in the side plates 9| and 93. The rod |99 is positioned in the slots |85 and |3511.

The lever |90 may be rotated in a counterclockwise direction as viewed in Fig. 1 about the shaft |95 from the position illustrated in Fig. 1 to the position illustrated in Fig. 2. In the latter position, the rod |99 engages stops 207| and 299 formed by extensions of the side walls 5 and 7. As a result of such movement of the lever |99, the rod |99 engages the front surfaces of the slots |95 and |8511 to force the bottom of the chart carriage in a forward direction to the position illustrated in Fig. 2. During the resulting movement of the chart carriageI it will be recalled that the cam followers |81 and 81a are forced out of` their associated recesses |83 and |33a and that the cam'surfaces |8| and |5|a ride down the cam followers to guide the chart carriage from the operative position illustrated in Fig. 1 to the intermediate position illustrated in Fig. 2.

By inspection of Fig. 2, it will be noted that in its intermediate position, the chart strip C and all parts of the chart carriage are completely clear of the recording pen i3. To retain the upper part of the chart carriage in operative position, the side walls 5 and are provided with slots 2| for reception of pins 2|3 which are carried respectively by the plates 9| and 93. These pins may be seen more clearly in Fig. 3. As the chart carriage moves from the operative position illustrated in Fig. 1 to the intermediate position illustrated in Fig. 2, the-pins 2|3 move out of their associated slots 2| The foregoing movement of the chart carriage to clear the recording pen eliminates the need for special mechanism for lifting the pen to clear the chart carriage. Furthermore, such movement permits the scale 41 to remain fixed in a position even though the target 45 normally is located in front of the scale. When the chart carriage is moved to operative position, it may raise the pen during the last portion of its movement. The location of the target in front of the scale facilitates the reading of the indications.

If it is desired to return the chart carriage from the position illustrated in Fig. 2 to the operative position illustrated in Fig. 1, the lever 99 is moved in a clockwise direction as viewed in Fig. 2 to force the cam surfaces |8| and lala. to ride up their associated cam followers |31 and Isla. This forces the chart carriage from the intermediate position illustrated in Fig. 2 to the operative position illustrated in Fig. i. During the last portion of the movement of the lever |99, the cam followers |31 and IS'ia are forced into their associated recesses |53 and |83a to retain the chart carriage in operative position. In addition, the. pins 2|3 move into their associated slots 2|| to retain the upper portion of 'the chart carriage in operative position.

It should be noted further that as the lever is actuated from the position illustrated in Fig. 2 to that shown in Fig. 1, the load applied by the chart carriage to the lever passes over the axis of rotation of the lever. In either position of the lever, the load thereon tends Yto maintain'the lever in the desired position.

By inspection of Fig. 2, it will be observed that when the chart carriage 3 is in the intermediate position it is free forforward pivotal movement in a counterclockwise direction about an axis parallel to the axes of the supply roll, the feed roll and the rewind roll. Such pivotal movement carries the chart carriage from the position illustrated in Fig. 2 to the position illustrated in Fig 3. In this movement, the chart carriage pivots about the rod |99 until the handle 29| again engages the side plates 9| and 93 to stop further pivotal movement of the chart carriage. In the position illustrated in Fig. 2, the lever |95 provides an extended stop for the chart carriage. Consequently, the chart carriage is securely held in the position illustrated in Fig. 3.

If it is desired to remove thechart carriage completely from the fixed unit the chart carriage may be grasped and moved in the direction of the arrow 2|5 (Fig. 3).l In response to such movement, the chart carriage completely clears its mounting and is completely removed from the associated xed unit Prior to such removal, any connections between the fixed unit and a motor mounted on the chart carriage (if an electrical motor) should be broken. A reversal of this procedure replaces the chart carriage in the position illustrated in Fig. 3. If it is desired to return the chart Vcarriage from theV sufces to retain the chart carriage in the intermediate position. In Fig. 3 the center of gravity of the chart carriage is on the left of the rod.

|99. Therefore, gravity retains thechart carriage in the position illustrated.

It wm be noted that with the `parte in the Y position illustrated in Fig. 2, the latches |59 and |6| may be manipulated to eject the rewind roll |93 for inspection and servicing. Also the rewind roll may be replaced after the desired inspection or servicing operations.

With the chart carriage in the position illustrated in Fig. 3, the supply roll 99 is accessible for removal and replacement.

may be rewound by inserting a suitablekey in an opening 2 6 provided in one of the side plates. Furthermore, the lever 6l may be actuated to move the inkwell 35 from, its operative to its service position. Such movement `of the lever 57 pivots the scale 4l to expose the recording pen I3 and to permit access to the electric lamp In addition, if y a spring wound motor is employed, the motor acuario:n

8|. The recording pen I3 then may be removed from its associated bracket I9. Also the inkwell may be raised from itsL bracket 51 and withdrawn for cleaning or other servicing operation.

Since the carriage, when in the position illustrated in Figs. 1 and 2, may be substantially surrounded by a casing 2|1, pins or handles 2I8 may be secured to the plates 9| and 93 to facilitate movement of the chart carriage from the positionv illustrated in Fig. 2 to the position illustrated in Fig. 3.

The casing 2|1 is shown more particularly in Figs. 8, 9 and l0. It will be noted that the casing includes a rectangular wall 2.|9 which is proportioned to surround the side walls and plates of the recording device. The rectangular Wall has, at its rear edge, a plurality of pins 22 I proportioned for reception in holes 223 which are provided in the base plateA 9 of the recording device. The casing 2|1 may be detachably or permanently secured to the base plate 9. For example, the pins may be projected through the holes 223 and their exposed ends may be upset to secure the rectangular wall 2I9 securely to the base plate 9.

The front opening of the rectangular wall 2I9 is covered by means of a cover 225 which is hinged at one side to the rectangular wall by suitable hinges 221. The cover is retained in closed position by a suitable latching bar 229 which is secured to the inner face of the cover by means of suitable machine screws 23|. These machine screws pass through slots 233 in the latching bar which are designed to permit a limited vertical movement of the latching bar.

Such movement is effected by rotation of a handle 235 projecting from the front of the cover. The handle 235 is mounted for rotation about an axis 231 and has an off-set pin 239 which projects through a horizontal slot 24| in the latch bar 229. Consequently, rotation of, the handle 235 in a clockwise direction, as viewed in Fig. 9, rotates the pin 239 in a counterclockwise direction, as viewed in Fig. l0, to lift the latch bar 229.

A spring wire 242 has its ends positioned in The central portion slots provided in the cover. of the wire engages the pin 239 to bias the handle 235 in a clockwise direction as viewed in Fig. 10.

In its latching position, the latch bar may cooperate with retaining tongues or lips secured to the rectangular wall 2|9 to retain the cover in closed position. For example, in Fig. 8 a retaining lip 243 is secured to the rectangular wall 2I9 in a position to overlie the latching bar 229. When the latching bar is lifted in response to rotation of the handle 235, the end of the latching bar clears the lip 243 to permit opening of the cover 225. The cover 225 may have a transparent window 245 of glass or other suitable material to permit inspection of the chart strip therethrough.

It is believed that the operation of the recording device is apparent from the foregoing description. With the parts in the position illustrated in Fig. l, the recording pen I3 rotates over the surface of the chart strip C to produce a record R thereon. In addition, the target 45 by its relationship to the scale 41 indicates at any instant the magnitude of the quantity being recorded. During this recording operation, the feed roll IOI continuously advances the chart strip from the supply roll 99 to the rewind roll |03.

If it is desired to inspect a portion of the record 14 wound on the rewind roll |03, the rewind roll may be ejected by proper rotation of the latches |59 and ISI. Alternately, if the rewindroll is driven by mechanism of the window-shade roller type previously discussed, the chart strip C may be pulled forward to unwind the desired partfrorn the rewind roll.

In order to service the recording device, the handle 20| of the lever |90 is actuated from the position illustrated in Fig. l to the position illustrated in Fig. 2. Rotation of the handle 20| actuates the rod |99 to move the lower part of the chart carriage with respect to the cam followers I81 and |81a. The cam followers ride out of their associated recesses |83 and I83a and along the inclined cam surfaces ISI and I8Ia to guide the chart carriage from the operative position illustrated in Fig. 1 to that illustrated in Fig. 2. With the parts in this position, the rewind roll |03 still can be ejected by proper rotation of the latches |59 and ISI. A reversal of the foregoing procedure may be employed for restoring the parts to the operative positions illustrated in Fig. 1.

If further servicing is required, the chart carriage may be moved from the intermediate position shown in Fig. 2 to the service position shown in Fig. 3 by grasping the pins 2I8- and rotating the chart carriage about the rod |99. The chart carriage is held in the position illustrated in Fig. 3 by means of the handle 20| and associated parts of the lever |90.

With the chart carriage in the service position illustrated in Fig. 3, the supply roll 99 may be removed for installation of a new chart strip. In addition, if a spring motor is employed for advancing the chart strip, it may be rewound by insertion of a suitable key through the opening 2I. It should be noted that the opening 2| 6 is clear of the casing 2|1 when the chart carriage is in the position illustrated in Fig. 3. If the chart carriage is to be removed completely, it is withdrawn in the direction of the arrow 2 I5.

If it is desired to reiill the inkwell, the inkwell may be moved from its operative position to its service position by rotation of the lever 61 in a clockwise direction as viewed in Fig. 3. The inkwell is shown in its service position in Fig. 3. Such movement of the lever 61 also pivots the scale 41 to expose parts of the recording device behind the scale. The inkwell may be removed for cleaning merely by lifting it from its supporting bracket. If an electrical lamp is to be replaced, the lamp holder is rotated to an accessible position and a replacement lamp is installed, after which the lamp holder may be restored to its operative position. rlihe recording pen I3 may be removed from its supporting bracket I9 by successive movements of the recording pen in an upward direction and a forward direction for cleaning or other servicing operations. By a reversal of the foregoing steps, the various parts may be returned to their operative positions.

It should be noted that when the parts are in their operative positions, the lip 61C of the lever E1 is located between the chart carriage and the front wall II. Because of this interlocking relationship, the inkwell cannot be disturbed until the chart carriage is moved away from its operative position.

Despite the fact that the casing 2|1 substantially surrounds the recording device, all parts requiring service are fully accessible from the front of the recording device. This means that accaesorV the recording device may be mounted flush in a suitable panel Without impairing the accessibility of parts. Furthermore, it will be noted that the structure permits the utilization of a wide chart. In a recording device designed for mounting on six inch centers, no diiiiculty has been encountered in providing a chart carriage capable of receiving a chart strip having a four inch scale.

If the chart carriage were designed to pivot about a vertical axis in its movement from the intermediate position to the service position the clearances required for such movement would make it diiiicult to provide a chart strip having the desired scale length. By moving the chart carriage in directions lying in planes perpendicular to the axes of the supply, feed and rewind rolls, optimum scale length is obtained.

It is desirable to provide different rates of advance for the chart strip. To this end, the gears |33 and |35 (Fig. 6) may be replaced by other gears providing diiTerent gear ratios. To facilitate replacement of the gears, the gears may be mounted on stub shafts accessible through openings provided in the side plate 9|. For example, the pinion |33 may be mounted on a shaft |33a which constitutes the motor shaft by means of a nut |331) which is in threaded engagement with the end of the shaft. The pinion |33 has a hub |33c which is provided With a slot |3311. This slot is positioned to receive a pin |33e attached to the shaft |3311. The bottom of the slot |33d has a coniiguration. Consequently, as the nut |3319 is rotated to secure the pinion |33 to the shaft |33a, the pinion |33e is forced into the V-shaped bottom or" the Slot to locate the pinion accurately with respect to the shaft. A similar structure may be employed for securing the gear |35 to the shaft |37.

Although the invention has been described with reference to certain specific embodiments thereof, numerous modifications thereof are possible. Therefore, the appended claims have been drafted to cover all modifications falling within the spirit and scope of the invention.

We claim as our invention:

1. In a recording device, a chart carriage, support means for the chart carriage, said chart carriage and said support means having coacting portions dening an axis about which the chart carriage is pivotable relative to the support means from a iirst positionto a second position displaced froni the first position, and means for locating said chart carriage normally in an operative recording position relative to the support means, wherein said coacting portions are displaced irom the relationship dening said axis, said chart carriage being movable from the recording position to said first position for permitting further movement of the chart carriage about said axis.

2. In a recording device, a chart carriage, support means for the chart carriage, said chart carriage and said support means having coacting pivot portions dening an axis about which the chart carriage is pivotable relative to the support means from a rst position to a second position displaced from the rst position, and means for locating said chart carriage normally in an operative recording position relative to the support means, wherein said coacting pivot portions are displaced from the relationship dening said axis, said chart carriage being movable from the recording position to said first position for permitting further movement of the chart carriage about said axis, said chart carriage and the support means, when in the second position, being separable in response to relative movement therebetween.

3. In a recording device, a chart carriage, support means for the chart carriage, said chart carriage and said support means having coacting portions dening an axis about Which the chart carriage is pivotable relative to the support means from a first position to a second position displaced from the first position, means for locating said chart carriage normally in an operative recording position relative to the support means, wherein said coacting portions are displaced from the relationship dening said axis, a recording element disposed on the support means to engage va chart carried by the chart carriage when the chart carriage is in said recording position, said chart carriage being movable from the recording position to said first position for clearing the recording element and for permitting further movement 0I" the chart carriage about said axis.

4. In a recording device, a chart carriage having drum means rotatable about an axis for engaging and advancing a chart strip, support means for the chart carriage, a recording element disposed on the support means to engage and produce a Arecord on a chart strip presented by the chart carriage, and guide means for guiding the chart carriage relative to the support means and the recording element successively in a first direction to clear the recording element and in a second direction to expose the chart carriage, said directions lying in planes substantially transverse to said axis.

5. In a recording device, a recording element disposed for movement substantially in a horizontal plane, a chart carriage having means for winding and unwinding about horizontal axes a chart strip, said chart carriage including guide means for guiding a chart strip through a substantially horizontal path wherein the chart strip engages the recording element, means for guiding the chart carriage in a substantially vertical direction away from the recording element to an intermediate position, said guiding means including means establishing an axis parallel to the rst-named horizontal axes about which the chart carriage can be moved relative to the recording element from said intermediate position for exposing the chart carriage.

6. In a recording unit, a chart carriage, a recording element, a support for the chart carriage and recording element, and means guiding the chart carriage for movement relative to the support in a iirst direction from operative position with respect to the recording element to an intermediate position clear o the recording element, said guiding means including means establishing an axis substantially transverse to the first direction about which the chart carriage is movable relative to the support between the intermediate position and a service position wherein the chart carriage is accessible.

'7. In a recording unit, a chart carriage, a recording element, a support for the chart carriage and recording element, and means guiding the chart carriage for movement relative to the support in a iirst direction from operative position with respect to the recording element to an intermediate position clear of the recording element, said guiding means including means tor moving the carriage from the intermediate position to the operative position, and means establishing an axis substantially transverse to the iirst direction about which the chart carriage is movable relative to the support between the intermediate position and a service position wherein the chart carriage is accessible.

8. In a recording unit, a chart carriage device, a recording element, a support device for the chart carriage and recording element, and means guiding the chart carriage for movement relative to the support in a rst direction from operative position with respect to the recording element to an intermediate position clear of the recording element, said guiding means including means establishing an axis substantially transverse to the first direction about which the chart carriage is movable relative to the support between the intermediate position and a service position wherein the chart carriage is accessible, cam means on one of said devices and cam follower means on the other of said devices, said cam and cam follower means coacting in response to relative movement therebetween for urging the chart carriage device between the intermediate and operative positions.

9. In a recording unit, a chart carriage, a recording element, a support for the chart carriage and recording element, and means guiding the chart carriage for movement relative to the support in a first direction from operative position with respect to the recording element to an intermediate position clear of the recording element, said guiding means including means establishing an axis substantially transverse to the rst direction about which the chart carriage is movable relative to the support between the intermediate position and a service position wherein the chart carriage is accessible, operating means comprising a member operable from a first position to a second position for urging the chart carriage between said operative position and said intermediate position, said member in its second position being located to stop and retain the chart carriage in the service position following movement of the chart carriage about said axis away from the intermediate position.

l0. In a recording unit, a chart carriage, a recording element, a support for the chart carriage and recording element, and means guiding the chart carriage for movement relative to the support in a first direction from operative position with respect to the recording element to an intermediate position clear of the recording element, said guiding means including means establishing an aXis substantially transverse to the first direction about which the chart carriage is movable relative to the support between the intermediate position and a service position wherein the chart carriage is accessible, operating means comprising a lever rotatable from a rst position to a second position for urging the chart carriage between said operative position and said intermediate position, the load of said chart carriage in its movement passing over the axis of rotation of the lever to maintain the lever in an operated position.

l1. A recording unit having a recording element in combination with a chart carriage device, a support device for the chart carriage and recording element, and means guiding the chart carriage for movement relative to the support in a first direction from operative position with respect to the recording element to an intermediate position clear of the recording element, said guiding means including means establishing an axis substantially7 transverse to the first direction about which the chart carriage is movable relative to the support between the intermediate position and a service position wherein the chart carriage is accessible, cam means on one of said devices and cam follower means on the other of said devices, said cam and cam follower means coacting in response to relative movement therebetween for urging the chart carriage device between the intermediate and operative positions, and said cam means being recessed to retain the cam follower means in the position corresponding to operative positions of the chart carriage until a substantial force has been apm plied to cause relative movement between the cam and cam follower means.

12. In a recording device, a chart carriage having drum means rotatable about an axis for engaging and advancing a chart strip, a recording element disposed to engage and produce a record on a chart strip presented by the chart carriage, guide means for guiding the chart carriage relative to the recording element successively in a first direction to clear the recording element and in a second direction to expose the chart carriage, said directions lying in planes substantially transverse to said axis, and means responsive to movement of the chart carriage from a position clear of the recording element to a position wherein the recording element engages a chart strip presented by the chart carriage for securing the chart carriage against movement in the second direction.

13.111 a recording device, a chart carriage having a pair of spaced substantially parallel side plates, chart strip supporting means cornprising drum means positioned between said plates and rotatable about an axis extending substantially perpendicular to the plates for engaging and advancing a chart strip, mounting means including a support for said chart carriage, a recording element mounted on the support for engaging a chart strip presented by the chart carriage when the chart carriage is in operative position relative to the support, means for guiding the chart carriage from operative position to an intermediate position clear of the recording element, said guiding means comprising cam surfaces formed on corresponding ends of the plates, and cam follower means on the support, said cam surfaces and cam follower means being positioned and proportioned to force said chart carriage from the intermediate position to the operative position in response to relative movement between the chart carriage and the support, said cam surfaces providing recesses for receiving the cam follower means when the chart carriage is in operative position for requiring a substantial force to displace the chart carriage from operative position, said mounting means including lever means pivotally mounted on said support for actuation between a first limiting position and a second position, said lever means engaging and moving the chart carriage relative to the support during such actuation to effect the relative movement between the cam surfaces and cam follower means reouired for urging the chart carriage from the intermediate position to said operative position, said mounting means and said chart carriage having coacting parts defining an axis parallel to said first-named avis about which the chart carriage may be pivoted from the intermediate position to a service position wherein parts of the chart carriage are displaced from the mounting means to permit access thereto, said lever means in its first limiting position beingy located to en,-

gage and retain the chart carriage in the service.

position, said chart carriage and the mounting means having engaging parts permitting re-. moval of the chart carriage from the mountingr means in response to movement of the chart carriage from its service position in a predetermined direction, and means responsive to movement ofV the chart carriage relative to the support from the intermediate position to the operative position for securing the chart carriage in operative position, said last-named means being releasable in response to movement of the chart carriage to the intermediate position for per.- mitting pivotal movement of the chart carriage relative to the mounting means towards. the service position.

14. In a recording device, a chart carriage having drum means rotatable about an axis for engaging and advancingr a chart strip, a recordingelement disposed to engage and produce4 a record on a chart strip presented bythe chart carriage, guide meansv for guiding the chart carriage relative to the recording element from an operative position successively in a rst directionto clear the recording element and in a second direction to expose the chart carriage, said directions lying in planes substantially transe verseV to said axis, an inkwell for supplying. ink to the recording element, a scale element cooperating with the recording element for indicating the magnitude of a quantity to be measured by the recording element, and linkage actuable for guiding the inkwell and scale element simultaneously from operative positions relative to the recording element to service positions displaced from the operative positions, said linkage being interlocked with the chart carriage to permit said actuation of the linkage only ifthe chart carriage is displaced from its operative position.

115i. In a recording device having parts service-V able fr-'om the front thereof, a support, measuring means having a vertical shaft rotatable in accordance With a quantity to be measured, a pen fi;

bracket associated with the shaft for rotation therewith, said pen bracket extending towards the front of the recording device, a recording pen releasably mounted on` the front end: of the bracket for pivotal movement about a horizontalaxis which is perpendicular to a plane containing the vertical axis, whereby the recording pen may be removed from the front of the re.- cording device, a scale, a target mounted for movement with the recording pen and bracket,

said target being disposed in front of the scale toindicate thereon the movementv of the pen bracket, means mountingv the scale for movement fromv thefront oi. the recording device out of proximity to the target to facilitate removal of the target-and recording pen, an inkwell for sup plyingl ink to the recording pen, meansA responsive to movement or the scale for moving the inkwell iijom its normal operative position to a position readily accessible from the front of the access .from the front ofv the recording dev-icerto,

parts ofthe chart carriage, ther inkwell and re-v cording pen.

16. In a recording. device for recording on a,v

chart element, a supporting structure,v a recording element, means mounting the recording element on the supporting structure for movement substantially in a horizontal plane when the re,- cording device is in operating condition, a chart carriage for presenting a substantially horizontal surface to the recording element, means mounting the chart carriage o n the supporting structure for movement substantially in a vertical direction relative to the supporting structure from an operating position for receiving arecord from the recording element towards an intermediate position clear of the recording element.

1'7. A recording device as, claimed in claim 16 in combination with actuating mechanism op erable for forcing thechart carriage from one to the other of said positions.

18. A recording deviceas claimed in claim 1 6, in combination with retaining means for sub-` stantially preventing movement oiy the chartcarriage relative to the supporting structure in a horizontal direction from said operating position, said retaining means being positioned to clearv Said chart oerriaeosubstarltially for movement irl ahorizontol dirootorl in responso to movement. of the ohortoarrioso to said intermediate P051- tion.

19- A recording device asfolonlodk in Claim. 16 in combination with ay casing for recording element, thesupporting structureand the chart carriage, said casing having a door which issubstan tially vertical when the recording device is in operating condition, said chart carriage and saidf, supporting structure* including pivot mechanism ei-Iective for guidingAv the chart carriage about a substantially horizontalaxis from saidk intermediate position towards the door.

20. A recording devicev as claimed inv claim 19 in combination` with an inkwell positioned within the casing for supplying ink tothe recording element, and inkwell control means operablefor moving the inkwell from its operating location towardsY the door.

2l.v A recording device as claimed in claim 20: in combination with interlocking means for preventing said operation of the inkwell control means, said interlocking means freeing the in k. well control means foroperation in response tov movement of the cheri? Carriage from operating position.

22. A recording device as, claimed in claim 20 wherein said inkwell` control means includes mechanism maintaining the inkwell level during the operation of the inkwell control means.

23. A recording device as claimed in claim 20v in combination with a scaleelement cooperating with the recording element,l for measuring displacement oi the recording. element, and meane responsivey to operation of the inkwell control means for` moving the s caleelernent from operating position relative to the. recording element.

24. In a recording device a. chart carriage, sup-Y port means .for the chart carriage, said chart car.- riage and. said support means having coacting portions defining an axis aboutwhich the chart carriageis pivotal from a rstpositionto a serv-Y iceposition, means effective. when the chart carriage is in the rst position for locating. the` chart carriage normally in an operative recording position relative to the support means, and means for supporting the chart carriage in the.

21 coasting portions being configured to permit separation of the chart carriage and the support means in response to a predetermined movement of the chart carriage from the service position relative to the support means.

25. A recording device as claimed in claim 24 in combination with a recording element movably mounted on the support means and operable for recording on a chart supported by the carriage in said recording position, said recording element being clear of the chart carriage when the chart carriage is in the service position, and acasing for the chart carriage, support means and recording element, said casing having a. door which opens to permit said separation of the chart carriage and removal of the chart carriage through the door opening.

DOUGLASS A. YOUNG. LAWRENCE J. LUNAS. JOHN WALSWEER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date Esterline Dec. 12, 1916 White et al Sept. 23, 1919 White et al Sept. 23, 1919 Brown Dec. 8, 1925 Bristol June 23, 1931 Blanchard -1 Mar. 1, 1932 Perry et a1. July 24, 1934 Spitzglass July 23, 1935 La Pierre Nov. 3, 1936 Beal Oct. 7, 1941 Nichols Jan. 19, 1943 Lee Jan. 8, 1946 

